Display Module Manufacturing Method and Display Module

ABSTRACT

A display module substrate and a manufacturing method thereof are provided. The display module substrate includes a substrate body and a plurality of signal circuits. The substrate body has a supporting surface. The supporting surface includes a viewing area and a signal circuit area on one side of the viewing area. The signal circuits are disposed on the supporting surface and located at the signal circuit area. The signal circuit area has a plurality of apertures running through the substrate body, wherein the apertures are not shielded by the signal circuits. In a manufacturing thereof, the substrate body is disposed on a transparent carrier plate. When high-energy light is applied through the transparent carrier plate to etch a bottom surface of the substrate body to separate the substrate body and the transparent carrier plate, the resulting gas leaves through the apertures.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention generally relates to a manufacturing method of asubstrate for display module. Particularly, the present inventionrelates to a manufacturing method of substrate for thin-type displaymodule.

2. Description of the Prior Art

Display devices have been extensively applied to various electricalproducts including computer, television, and communication devices; inaddition, the display devices are getting small, thin and light due tothe advancement of industrial technology and the user demand. Apart fromthe usual plane-surface character, display panels nowadays further havecurved or flexible feature and go with variable display device designs,or provided for display device development. The display device itselfmay namely be the major part and accompanied with functions such as wordprocessing, communication and data processing.

With regard to the manufacture of flexible display panel/display device,it is generally to form or cut a flexible substrate first (whereinforming the flexible substrate includes coating on a glass plate withoutcutting), then to dispose circuits, illumination material and/or lightsources on the substrate. However, the flexible substrate itself may notbe suitable for the high-temperature manufacturing process; accordingly,inflexible sheet materials may be required to serve as a carrier of theflexible substrate. After the manufacturing process is completed,releasing of the flexible substrate from the carrier is conducted byhigh-energy laser. However, heat and gas which accompany high-energylaser in the releasing process may cause the deformation of thesubstrate that changes the pitch of the bonding pads in the fan-out areaand raises the difficulty of the following processes.

SUMMARY OF THE INVENTION

It is an object of the present invention to provide a display modulesubstrate which has less deformation.

It is another object of the present invention to provide a manufacturingmethod of a display module which alleviates the deformation of productand improves the yield of product.

The display module substrate of the present invention includes asubstrate body and a plurality of signal circuits. The substrate has asupporting surface. The supporting surface includes a viewing area and asignal circuit area on one side of the viewing area. The signal circuitsare disposed on the supporting surface and located at the signal circuitarea. The signal circuit area has a plurality of apertures runningthrough the substrate body, wherein the apertures are not shielded bythe signal circuits.

The manufacturing method of the display module substrate of the presentinvention includes (a) disposing a substrate body on a transparentcarrier plate; wherein the substrate body has a bottom surface and asupporting surface opposite to the bottom surface, the bottom surface isattached to the transparent carrier plate, the supporting surfaceincludes a viewing area and a signal circuit area; (b) disposing aplurality of signal circuits in the signal circuit area; (c) forming aplurality of apertures in the signal circuit area, the apertures runningthrough the substrate body and not shielded by the signal circuits; (d)etching the bottom surface by high-energy light through the transparentcarrier plate to separate the substrate body from the transparentcarrier plate.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows a top view of an embodiment of the display module substrateof the present invention;

FIG. 2 is a partial three-dimensional view of the embodiment of FIG. 1;

FIG. 3 is a cross-sectional view of the embodiment of FIG. 2 along theAA line;

FIG. 4 shows a bottom view of the embodiment of the display modulesubstrate of the present invention;

FIG. 5 shows a flow chart of the manufacturing process of display modulesubstrate of the present invention;

FIGS. 6-7 show schematic views of the manufacturing process of displaymodule substrate of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

As shown in FIGS. 1-2, the display module substrate of the presentinvention includes a substrate body 100 and a plurality of signalcircuits 350. The substrate body 100 has a supporting surface 150; thesignal circuits 350 are disposed on the supporting surface 150. On theother hand, the substrate body 100 has a bottom surface 160 opposite tothe supporting surface 150. In detail, the substrate body 100 may be aplastic material and preferably flexible. In a preferred embodiment, thesubstrate body 100 may be in the form of plastic thin film. Material forthe substrate body can be, for example, polyimide (P1). In addition, thedisplay module substrate 10 may be, for example, the substrate for LCD(Liquid Crystal Device) display module, the substrate of OLED (OrganicLight-Emitting Diode), but not limited thereto.

The supporting surface 150 of the substrate body 100 includes a viewingarea 200 and a signal circuit area 300, wherein at least a portion ofthe signal circuit area 300 may be a fan-out area and/or an IC(integrated circuit) bonding area. IC(s) may be disposed on the fan-outarea by means of such as COG (chip on glass), COF (chip on film) andothers. The plurality of signal circuits 350 is disposed on the signalcircuit area 300. Preferably, the plurality of signal circuits 350 crowdtogether on the signal circuit area 300 and form at least a crowd. Takethe embodiments shown in FIGS. 1-2 for example; the plurality of signalcircuits 350 forms five crowds on the signal circuit area 300 and thesignal circuits 350 in each crowd are distributed according to aspecific pattern. For example, multiple signal circuits 350 in the crowdextend and simultaneously converge toward the pads 380 to constitute asignal crowd in the shape of trapezoid-like or fan-like.

The signal circuit area 300 may be on one side of the viewing area 200and usually distributed along the side of the viewing area 200. In otherembodiments, the viewing area 200 may have more than one side with thesignal circuit area 300 distributed.

The viewing area 200 of the supporting surface 150 may further includeelectrodes and/or driving elements such as TFT (Thin-Film Transistor),liquid crystals, illumination material and/or color filter. The signalcircuits 350 on the signal circuit area 300 may be electricallyconnected to the electrodes and/or driving elements; in addition, adriving circuit of the display module such as IC driver may be connectedto the signal circuits 350 on the signal circuit area 300 of thesubstrate body 100.

As shown in FIGS. 3-4, the signal circuit area 300 further has aplurality of apertures 360 running through the substrate body 100. Inother words, openings of the apertures 360 are on the supporting surface150 and the bottom surface 160, wherein depth of the apertures ispreferably 5-100 micrometers and is substantially equal to the thicknessof the substrate body 100. Multiple apertures 360 which preferably havea diameter W of not less than 1 micrometer may be formed on thesubstrate body 100 by means of drilling approaches, such as lasercutting and punching, wherein a distance D between the adjacentapertures 360 are preferably not less than 1 micrometer (in FIG. 3, thedistance D is shown from the left end of one aperture to the left end ofthe adjacent aperture; alternatively, the distance D can be shownbetween the centerlines of the adjacent apertures). On the other hand,the apertures 360 are not shielded by the signal circuits 350 on thesignal circuit area 300; for example, the apertures 360 are formedbetween the adjacent signal circuits 350. In the embodiment of thepresent invention, at least a portion of the apertures 360 are locatedbetween the adjacent signal circuits 350. When the plurality of signalcircuits 350 in the signal circuit area 300 form the crowds such as thesignal crowd in the shape of fan as mentioned above, the apertures 360located in the crowds and between the adjacent signal circuits 350 maybe distributed in the shape of fan.

As mentioned above, the substrate body 100 has the bottom surface 160opposite to the supporting surface 150. Preferably, notches S are formedon the bottom surface 160. The notches S may be resulted fromhigh-energy light etching such as laser etching. Further, the notches Sare preferably distributed on a portion of the bottom surface 160 thatcorresponds to the signal circuit area 300 on the opposite supportingsurface 150. The apertures 360 runs through the substrate body 100 andhave openings on the supporting surface 150 and the bottom surface 160;the openings of the apertures 360 are further in the signal circuit area300 of the supporting surface 150 and the portion of the bottom surface160, wherein the portion of the bottom surface 160 corresponds to thesignal circuit area 300, i.e. a portion of the supporting surface 150which is just opposite to the portion of the bottom surface 160 has thesignal circuit area 300. The openings of the apertures 360 on the bottomsurface 160 area are surrounded by the notches S.

In the preferred embodiment of the present invention, the apertures 360and the notches S may be resulted from the formation of the displaymodule substrate 10 or remained therefrom. Further, the apertures 360are the structures which the display module substrate 10 needs in areleasing process, wherein the apertures 360 may serve as passages forgas exhausting. The notches S are traces resulted from the releasingprocess carried out by laser. The manufacturing method of the displaymodule substrate 10 are further described as followings.

As the embodiment shown in FIG. 5, the manufacturing method of thedisplay module substrate 10 of the present invention may include step510 of disposing a substrate body on a transparent carrier plate,wherein the substrate body has a bottom surface and a supporting surfaceopposite to the bottom surface. The bottom surface is attached to thetransparent carrier plate; the supporting surface includes a viewingarea and a signal circuit area on one side of the viewing area.

Since the substrate body 100 of the display module substrate 10 isflexible and usually has poor tolerance to high temperature, a carrierplate is provided to assist in the manufacture of the display modulesubstrate. The carrier plate preferably has transparency and may be, forexample, a glass plate. Light energy may be used during a releasingprocess. In addition, the substrate body 100 may be directly formed onthe carrier plate, such as the transparent carrier plate 400 shown inFIG. 6. For example, material for the substrate body 100 may be coatedon the transparent carrier plate 400 to form the substrate body 100.

The formed substrate body 100 has a bottom surface 160 and a faceexposed outsides. As shown in FIG. 6(b), the bottom surface 160 isattached to the surface of the transparent carrier plate 400; the faceexposed outsides will be the supporting surface 150. The supportingsurface 150 is divided into several parts and at least into the viewingarea 200 and the signal circuit area 300.

On the other hand, the step 510 preferably further includes disposing asacrificial layer 500 or water-resistant layer on the transparentcarrier plate (please refer to FIG. 7). The sacrificial layer may beformed directly on the transparent carrier plate; for example, amaterial such as an inorganic material for the sacrificial layer iscoated on the substrate body to form the sacrificial layer. Thesacrificial layer is formed between the substrate body and thetransparent carrier plate; in other words, the substrate body isdisposed on the sacrificial layer when the sacrificial layer is disposedon the transparent carrier plate. The sacrificial layer preferably hastwo opposite surfaces attached to the transparent carrier plate and thesubstrate body, respectively. The sacrificial layer may be an expendableto relieve loss of the substrate body during the releasing process.

The manufacturing method of the display module substrate 10 of thepresent invention further includes step 520 of disposing a plurality ofsignal circuits on the signal circuit area.

Preferably, the step 520 further includes disposing electrode(s) and/ordriving element(s) on the supporting surface 150. In the preferredembodiment of the present invention, as shown in FIG. 6(c), TFT array610 are formed on the supporting surface 150, wherein a plurality ofsignal circuits of the TFT array 610 are disposed on the signal circuitarea 300. Preferably, the plurality of signal circuits 350 crowdtogether in the signal circuit area 300 to form at least one crowd. Theplurality of signal circuits 350 in the at least one crowd aredistributed specifically in shape. For example, multiple signal circuits350 in the crowd extend and simultaneously converge toward the pads 380to constitute a circuit crowd in the shape of trapezoid-like orfan-like.

In addition, the manufacturing method of the display module 10 of thepresent invention may further include disposing such as liquid crystals,illumination material, filter and/or film encapsulation. Take theembodiment shown in FIG. 3 for example. In the preferred embodiment ofthe present invention, organic illumination material is further disposedon the supporting surface 150, wherein an organic layer 620 is formed bysuch as vapor or liquid phase deposition and coating; it is preferred tofrom thin film encapsulation 630 outsides the organic layer 620. Thedisplay module substrate 10 manufactured in this way may serve assubstrate for OLED.

The manufacturing method of the display module substrate 10 of thepresent invention further includes step 530 of forming a plurality ofapertures in the signal circuit area, wherein the apertures run throughthe substrate body and are not shielded by the signal circuits. When thesacrificial layer is disposed between the substrate body and thetransparent carrier plate, the apertures may further run through thesacrificial layer. Multiple apertures 360 which preferably have adiameter W of not less than 1 micrometer may be formed on the substratebody 100 by means of drilling approaches such as laser cutting andpunching, wherein a distance D between the adjacent apertures 360 arepreferably not less than 1 micrometer. Take the embodiment shown in FIG.6 for example; the drilling starts from the side of the substrate body100 opposite to the transparent carrier plate 400, i.e. the supportingsurface 150. Further, the drilling is carried out in the signal circuitarea 300 of the supporting surface 150 (alternatively, the drilling maybe carried out from a bottom face of the glass plate) and keeps awayfrom the signal circuits 350. The drilling preferably acts on aninterface of the transparent carrier plate 400 and the substrate body100 so as to ensure the formation of the apertures 360 running throughthe substrate body 100. The apertures 360 may be located at spacebetween the adjacent signal circuits 350. When the plurality of signalcircuits 350 crowd together in the signal circuit area 300 such as crowdtogether to form the signal crowd in the shape of fan-like, theapertures distributed therein may accordingly constitute the shape offan.

The manufacturing method of the display module substrate 10 of thepresent invention further includes step 540 of etching the bottomsurface by high-energy light through the transparent carrier plate toseparate the substrate body from the transparent carrier plate. The step540 is also called the releasing process. In the preferred embodiment ofthe present invention, the high-energy light may be laser such as UVlaser. Please refer to both FIGS. 6(e) and 7; high-energy light E may beemitted from one side of the transparent carrier plate 400 that isopposite to the substrate body 100 and through the transparent carrierplate 400. Energy of the high-energy light is sufficient to pass throughthe transparent carrier plate 400, wherein the high-energy lightpreferably arrives at the interface of the transparent carrier plate andthe substrate body 100.

Further speaking, the high-energy light E may penetrate at least aportion of the transparent carrier plate 400, wherein a portion of thesubstrate body 100 supported by the portion of the transparent carrierplate 400 has the signal circuit area 300 on the opposite supportingsurface 150. Accordingly, the high-energy light E may penetrate thetransparent carrier plate 400 and arrive at a portion of the bottomsurface 160, wherein the portion of the bottom surface 160 correspondsto the signal circuit area 300 of the supporting surface 150 on oppositeside. The high-energy light E may decompose or damage the bottom surface160 by which the substrate body 100 is attached to the transparentcarrier plate 400 and release the attachment of the substrate body 100and the transparent carrier plate 400, which results in separation ofthe substrate body 100 and the transparent carrier plate 400. Theprocess is usually accompanied by generation of heat and gas P. Inaddition, the high energy may also result in notches due to a scanningpath.

The gas P may come from the decomposition and/or vaporization of thesubstrate body 10, wherein the molecules of gas P may be the moleculesof carbon group. The gas P first appears between the substrate body 100and the transparent carrier plate 400 and is able to escape and leaveaway from a space A between the substrate body 100 and the transparentcarrier plate 400. Accordingly, it is not easy for the substrate body100, especially the portion of the substrate body 100 having the signalcircuit area 300 to deform due to synergy effect resulted from the gas Pand gas in the small space A. Specifically, the deformation may be anexpansion of the substrate body 100 resulted from pressure and heatcoming from the direction of the transparent carrier plate 400.

On the other hand, when the sacrificial layer is disposed between thesubstrate and the transparent carrier plate, the high-energy light E maybe emitted from a side of the transparent carrier plate 400 opposite tothe sacrificial layer 500. The energy of the high-energy light issufficient to pass through the transparent carrier plate 400, whereinthe high-energy light preferably arrives at an interface of thetransparent carrier plate 400 and the sacrificial layer 500. The highenergy light E may decompose or damage the sacrificial layer 500 torelease the attachment of the substrate body 100 and the transparentcarrier plate 400 and separate the substrate body 100 and thetransparent carrier plate 400 from each other. In addition, loss of thesubstrate body 100 in the releasing process is therefore reduced by thedeposition of the sacrificial layer 500.

In comparison to variation of the pitch between the pads of theconventional signal circuit area due to deformed substrate body, theapertures 360 of the substrate body 100 can reduce the variation.Because of the releasing process of the present invention, improvementin the substrate body 100 and the element thereon further improves thesubsequent processes and therefore increase the yield of the displaymodule substrate.

On the other hand, in the preferred embodiment of the present invention,the high-energy light E may be emitted into the transparent carrierplate 400 in the extension direction of the signal circuit area 300(i.e. the longer side) that accordingly separates a portion of thesubstrate body 100 along the extension direction from the transparentcarrier plate 400. In addition, the laser may substantially scan theplate in accordance with the width direction of the signal circuit area300. Following the laser's moving, as shown in FIG. 7, portions of thesubstrate body 100 in the width direction of the signal circuit area 300substantially separate from the transparent carrier plate.

As shown in FIG. 4, the notches S resulted from the etching of thebottom surface 160 by the high-energy light surround the apertures 360,wherein a portion of the bottom surface 160 having the notches Sreflects where the high-energy light E acts on. That is, the high-energylight acts in the vicinity of the apertures 360 and a portion of thesubstrate body around the apertures 360; accordingly, molecules of gas Presulted from vaporization of the portion of the substrate body 10 mayescape through the apertures 360.

As shown in FIG. 6(f), after the step 540, the substrate body 100 iseasily separated from the transparent carrier plate 400 to accomplishthe manufacture of the display module substrate 10. Alternatively, afterthe step 540, a driving circuit can be disposed on the substrate body100/display module substrate 10.

Although the preferred embodiments of present invention have beendescribed herein, the above description is merely illustrative. Thepreferred embodiments disclosed will not limit the scope of the presentinvention. Further modification of the invention herein disclosed willoccur to those skilled in the respective arts and all such modificationsare deemed to be within the scope of the invention as defined by theappended claims.

What is claimed is:
 1. A manufacturing method of a display modulesubstrate, including: (a) disposing a substrate body on a transparentcarrier plate, wherein the substrate body has a bottom surface and asupporting surface opposite to the bottom surface, the bottom surface isattached to the transparent carrier plate, the supporting surfaceincludes a viewing area and a signal circuit area; (b) disposing aplurality of signal circuits in the signal circuit area; (c) forming aplurality of apertures in the signal circuit area, wherein the aperturespenetrate through the substrate body, and at least a portion of theapertures are located between the adjacent signal circuits anddistributed along an extension direction of the signal circuits; (d)etching the bottom surface by high-energy light through the transparentcarrier plate to separate the substrate body from the transparentcarrier plate.
 2. The manufacturing method of claim 1, furtherincluding: (e) disposing a driving circuit in the signal circuit areaafter separating the substrate body from the transparent carrier plate.3. The manufacturing method of claim 1, further comprising disposing asacrificial layer on the transparent carrier plate and disposing thesubstrate body on the sacrificial layer.
 4. The manufacturing method ofclaim 1, wherein the step (b) further includes arranging the signalcircuits in a fan-like shape, so the apertures located between thesignal circuits are also arranged in a fan-like shape.
 5. Themanufacturing method of claim 1, wherein the step (d) further includesforming notches on the bottom surface.
 6. The manufacturing method ofclaim 1, wherein the step (c) includes forming the apertures to have adiameter not less than 1 μm.
 7. The manufacturing method of claim 1,wherein the step (c) includes forming the apertures to have a distancebetween the adjacent apertures not less than 1 μm.